Produce dealers signal prices through secret hand-gesture codes

Evidence

Each group has a secret code for communicating prices: a finger in the mouth may signify a 20 lire discount, the sign for scissors means 200, the name Via Cavour 600. — Diego Gambetta, The Sicilian Mafia The Business of…, 549

Categorization

• CANDY: Finger-in-mouth for 20 lire off is a wonderfully tweetable detail about how markets communicate without words.